Main changes are in the top-level organization of sections and the documentation appearance - it has been tweaked to look a bit nicer and more consistent. This is still undergoing effort, so it will probably still take some time until all the pages have been reviewed and changed, but what we have there now looks like a good beginning. All remarks and suggestions are most welcome - preferred place to publish them is documentation board on the forum.

We are also introducing a significant change in the way how documentation updating process will be handled. From now on, we will have separate documentation for each major version of CiviCRM (2.2, 2.3, etc). Long term goal for introducing this procedure is to make our docs simpler, relevant to only one version (right now the documentation refers to multiple versions, which introduces some confusion), also easier to maintain. Hopefully, the next step will be introducing regular review process that will help us assure that the docs are clean and up to date.

How does it look like in practice? At the moment, there are three versions of documentation available:

Addresses will stay the same as we will be introducing new versions - CRMDOC will always take you to currently promoted (stable or late beta) version, CRMUPCOMING will be always "work in progress" documentation for new version, and all the old versions will be name with CRMDOC plus version number (like CRMDOC21). The address: http://documentation.civicrm.org/ will always take you to main version of the documentation. Also, once you get to the main version of documentation, it's quite easy to navigate to any other version available.

And since we are at documentation, here's a small leak on the news that will show up on the blog soon - we will soon start work on providing a CiviCRM book. Now, that's really exciting! :-)